Unlocking cellulose structure disassembly via localized strong adsorption on solid acids for enhanced hydrolysis

The effective hydrolysis of cellulose is crucial for valorizing biomass; however, the efficiency of traditional solid acid catalysts is often limited by insufficient adsorption and activation of cellulose. Inspired by the cellulose-binding domain of cellulase, which can disrupt the aggregate structure of cellulose, we used a one-pot hydrothermal method to synthesize carbon-based solid acid catalysts rich in boronic acid hydroxyl (B-OH) and carboxyl (-COOH) groups using furanboronic acid and methylglyoxal as precursors. Catalytic performance evaluation indicates that surface -OH groups (B-OH and C-OH, including phenolic -OH) effectively unlock the aggregate structure of cellulose, significantly improving mass transfer efficiency and thereby promoting cellulose conversion. The optimal catalyst, A1B1@C, achieved a 98.9% cellulose conversion and a 44.7% glucose yield within 4 h in pure water at 180 °C. Mechanistic studies revealed that surface hydroxyl groups, including B-OH and C-OH, collectively disrupt the internal hydrogen-bond network of cellulose through strong adsorption and anchoring. Among them, B-OH is a characteristic and strong binding component. In contrast, the adjacent -COOH groups hydrolyze the exposed glycosidic bonds. Furthermore, the catalyst exhibited excellent cycling stability. This work highlights the critical role of adsorption capacity in solid acid-mediated cellulose conversion and provides a new design strategy for such catalysts.